.\"
.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for
.\" permission to reproduce portions of its copyrighted documentation.
.\" Original documentation from The Open Group can be obtained online at
.\" http://www.opengroup.org/bookstore/.
.\"
.\" The Institute of Electrical and Electronics Engineers and The Open
.\" Group, have given us permission to reprint portions of their
.\" documentation.
.\"
.\" In the following statement, the phrase ``this text'' refers to portions
.\" of the system documentation.
.\"
.\" Portions of this text are reprinted and reproduced in electronic form
.\" in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
.\" Standard for Information Technology -- Portable Operating System
.\" Interface (POSIX), The Open Group Base Specifications Issue 6,
.\" Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
.\" Engineers, Inc and The Open Group.  In the event of any discrepancy
.\" between these versions and the original IEEE and The Open Group
.\" Standard, the original IEEE and The Open Group Standard is the referee
.\" document.  The original Standard can be obtained online at
.\" http://www.opengroup.org/unix/online.html.
.\"
.\" This notice shall appear on any product containing this material.
.\"
.\" The contents of this file are subject to the terms of the
.\" Common Development and Distribution License (the "License").
.\" You may not use this file except in compliance with the License.
.\"
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
.\" or http://www.opensolaris.org/os/licensing.
.\" See the License for the specific language governing permissions
.\" and limitations under the License.
.\"
.\" When distributing Covered Code, include this CDDL HEADER in each
.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
.\" If applicable, add the following below this CDDL HEADER, with the
.\" fields enclosed by brackets "[]" replaced with your own identifying
.\" information: Portions Copyright [yyyy] [name of copyright owner]
.\"
.\"
.\" Copyright 1989 AT&T
.\" Portions Copyright (c) 1992, X/Open Company Limited  All Rights Reserved
.\" Copyright (c) 2008, Sun Microsystems, Inc.  All Rights Reserved
.\"
.TH MQ_SETATTR 3C "Feb 5, 2008"
.SH NAME
mq_setattr \- set/get message queue attributes
.SH SYNOPSIS
.LP
.nf
#include <mqueue.h>

\fBint\fR \fBmq_setattr\fR(\fBmqd_t\fR \fImqdes\fR, \fBconst struct mq_attr *\fR\fImqstat\fR,
     \fBstruct mq_attr *\fR\fIomqstat\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBmq_setattr()\fR function is used to set attributes associated with the
open message queue description referenced by the message queue descriptor
specified by \fImqdes\fR.
.sp
.LP
The message queue attributes corresponding to the following members defined in
the \fBmq_attr\fR structure are set to the specified values upon successful
completion of \fBmq_setattr()\fR:
.sp
.ne 2
.na
\fB\fBmq_flags\fR \fR
.ad
.RS 13n
The value of this member is either \fB0\fR or  \fBO_NONBLOCK.\fR
.RE

.sp
.LP
The values of \fBmq_maxmsg\fR, \fBmq_msgsize\fR, and \fBmq_curmsgs\fR are
ignored by \fBmq_setattr()\fR.
.sp
.LP
If \fIomqstat\fR is non-\fINULL\fR, \fBmq_setattr()\fR stores, in the location
referenced by \fIomqstat\fR, the previous message queue attributes and the
current queue status. These values are the same as would be returned by a call
to \fBmq_getattr()\fR at that point.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fBmq_setattr()\fR returns \fB0\fR and the
attributes of the message queue will have been changed as specified. Otherwise,
the message queue attributes are unchanged, and the function returns
\fB\(mi1\fR and sets \fBerrno\fR to indicate the error.
.SH ERRORS
.sp
.LP
The \fBmq_setattr()\fR function will fail if:
.sp
.ne 2
.na
\fB\fBEBADF\fR \fR
.ad
.RS 11n
The \fImqdes\fR argument is not a valid message queue descriptor.
.RE

.sp
.ne 2
.na
\fB\fBENOSYS\fR \fR
.ad
.RS 11n
The \fBmq_setattr()\fR function is not supported by the system.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
_
MT-Level	MT-Safe
_
Standard	See \fBstandards\fR(7).
.TE

.SH SEE ALSO
.sp
.LP
.BR msgctl (2),
.BR msgget (2),
.BR msgrcv (2),
.BR msgsnd (2),
.BR mq_getattr (3C),
.BR mq_open (3C),
.BR mq_receive (3C),
.BR mq_send (3C),
.BR mqueue.h (3HEAD),
.BR attributes (7),
.BR standards (7)
.SH NOTES
.sp
.LP
Solaris 2.6 was the first release to support the Asynchronous Input and Output
option. Prior to this release, this function always returned \fB\(mi1\fR and
set \fBerrno\fR to \fBENOSYS\fR.
